1. Field of the Invention
The invention relates to a system for supplying electrical power to electrically propelled public transport vehicles and in particular to supplying electrical power to trams.
2. Description of the Prior Art
Our patent application FR-A1 2 782 680 discloses a system for supplying power to electrically propelled vehicles enabling public transport vehicles, such as high-capacity trams, to circulate without an overhead line DC power supply. This kind of system includes an autonomous power supply system on board the vehicle consisting of an electric motor provided with a high-mass flywheel and stations with a mains electrical power supply for recharging the flywheel with energy.
This kind of flywheel on board a rail vehicle has the disadvantage of requiring a bulky suspension system for damping its strong gyroscopic torque, which can interfere with the dynamic behavior of the vehicle, and protection means to limit mechanical and thermal hazards in the event of a breakdown. What is more, in this kind of installation, the mains power supply at the stations is heavily loaded when recharging the flywheel during stops, which makes it obligatory to have powerful and costly electrical power supply infrastructures at the stations to prevent overloading the mains electrical power supply.
The invention therefore aims to remedy these disadvantages by proposing a system for supplying an electrically propelled vehicle with electrical energy that enables fast charging of an autonomous power supply device on board the vehicle with electrical power supply infrastructures at the stations of modest power that are simple and economical to produce.
The invention provides a power supply system for an electrically propelled vehicle equipped with electric traction motors including an autonomous power supply system which can be recharged on board the vehicle for supplying power to the electric traction motors, at least one station provided with an electrical power supply system connected to the mains electrical power supply network and connection means for electrically connecting the autonomous power supply system of the vehicle, on approaching the station, to the power supply system of the station in order to charge the autonomous power supply device when the vehicle is stopped in the station, characterized in that the autonomous power supply system on board the vehicle includes a battery of supercapacitors and in that the power supply system of the station includes an energy accumulating kinetic system.
Particular embodiments of the power supply system can have one of more of the following features, individually or in any technically feasible combination:
the energy accumulating kinetic system recovers braking energy of the vehicle when the vehicle is approaching the station;
the energy accumulating kinetic system supplies energy to the autonomous power supply system of the vehicle when the vehicle is accelerating on leaving the station;
the connecting means consist of an overhead line in each station cooperating with a pantograph carried by the vehicle, with a return current path via the wheels and the rails.
The aims, aspects and advantages of the present invention will become clearer after reading the following description of one embodiment of the invention, which description is given by non-limiting example and with reference to the accompanying drawings.